When land vegetation or biomass (i.e., biological mass) burns, aerosols and trace gases, such as CO, CO2, and CH4, are released to the atmosphere. These are important for atmospheric composition, and these trace gases are a fundamental part of the carbon cycle. The irradiance from biomass burning for flaming fires at approximately 1,000 K and smoldering fires at approximately 600 K, both peak in the atmospheric window from 3.5 to 4.0 μm. See, for example, graph 100 shown in FIG. 1. By comparing the radiance at 3.5-4.0 μm with the radiance at 10-12 μm, the temperature of the fire can be measured. Simply put, the temperature of the fire can be determined by taking the ratio of the intensity in the 3.5-4.0 μm channel to the intensity in the 10-12 μm channel. Thus, a shortwave infrared channel at the 3.5-4.0 μm wavelength, together with a thermal channel at 11 μm, are key to obtaining better data for determining (1) the area of the biomass-burning fire, especially for smaller fires, and (2) the temperatures of combustion.
These two fire variables determine the types and quantities of aerosols and also the quantity of CO, CO2, and CH4 released from fires. These two channels would benefit inventory-based methods for estimating fire emissions (i.e., those not considering combustion temperatures and radiative power) by affording the ability to distinguish between different fire types such as cropland fires, prescribed forest management fires, and deforestation fires.
However, the thermal channels on ASTER are not optimized for biomass burning, while the MODIS instruments have optimally placed thermal channels with spatial resolutions of 1000 m.
Thus, an alternative approach may be beneficial.